Nickel base superalloy GH4049 prepared by powder metallurgy

The process of preparing nickel base superalloy GH4049 from atomized prealloyed powder is studied. The results show that the compacts with relative density over 99% can be made by sintering at 1350 °C for 2 h in vacuum. Sintering in vacuum is better than that in argon atmosphere. The sintering way is supersolidus liquid phase sintering. The tensile strength and yield strength and ductility are about 1113 MPa and 760 MPa and 13% respectively. They are near the wrought superalloy GH4049. There are two kinds of γ′ phase precipitated in the grains. The rectangular γ′ phase is about 200 nm and the global γ′ phase is about 40 nm. The average grain size is below 80 μm. Its property of the compression stress relaxation at 850 °C is better than wrought cobalt base superalloy GH605 (L-605). The results lay the foundation of near-net-shape forming for the powder nickel superalloy GH4049.